BoardChemistry

Aldehydes, Ketones and Carboxylic Acids

7 Board Chemistry previous year questions on Aldehydes, Ketones and Carboxylic Acids — options free on every question; 1 include the answer & explanation free, the rest unlock with PYQ Pass.

Q1 FREE PREVIEW
PYQ

\({\mathrm{CH}}_{3}-\mathrm{C}\equiv \mathrm{CH}\overset{\mathrm{Pd}/\mathrm{C}}{\underset{{\mathrm{H}}_{2}}{\to }}\mathrm{A}\overset{(\mathrm{i}){\mathrm{O}}_{3}}{\underset{(\mathrm{ii})\mathrm{Zn},{\mathrm{H}}_{2}\mathrm{O}}{\to }}\mathrm{B}+\mathrm{C}\)

Products B and C are :

Memory Based Question 28/Jan/25 Evening shift

a

Ethanal and formaldehyde

b

Propanal and formaldehyde

c

Ethanal and propanal

d

Propanal only

✓ Correct answer: a)

Ethanal and formaldehyde

Explanation

Step 1: Hydrogenation (H₂/Pd-C)
Propyne (CH₃-C≡CH) undergoes partial hydrogenation to form propene (CH₃-CH=CH₂).

Step 2: Ozonolysis (O₃/Zn, H₂O)
Ozonolysis cleaves the C=C bond in propene, producing:
- Ethanal (CH₃CHO)
- Formaldehyde (HCHO)

Thus, the correct answer is: (A) Ethanal and Formaldehyde.

Q2
PYQ

Both acetaldehyde and acetone (individually) undergo which of the following reactions?
A. Iodoform Reaction
B. Cannizzaro Reaction
C. Aldol Condensation
D. Tollen's Test
E. Clemmensen Reduction

Choose the correct answer from the options given below

a

A, B and D Only

b

A, C and E Only

c

B, C and D Only

d

C and E Only

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Q3
PYQ

Which of the following arrangements with respect to their reactivity in nucleophilic addition reaction is correct?

a

acetophenone < p-tolualdehyde < benzaldehyde < p- nitrobenzaldehyde

b

acetophenone < benzaldehyde < p-tolualdehyde < p- nitrobenzaldehyde

c

benzaldehyde < acetophenone < p- nitrobenzaldehyde < p-tolualdehyde

d

p-nitrobenzaldehyde < benzaldehyde < p-tolualdehyde < acetophenone

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Q4
PYQ

Both acetaldehyde and acetone (individually) undergo which of the following reactions,
A) lodoform Reaction
B) Cannizzaro Reaction
C) Aldol condensation.
D) Tollen's test
E) Clemmesen Reduction

Memory Based Question 28/Jan/25 Morning shift

a

A, C & E only

b

A, D & E only

c

A, B, C, D & E

d

A & C only

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Q5
PYQ

Consider the following sequence of reaction\({\mathrm{C}}_{6}{\mathrm{H}}_{12}\overset{\mathrm{Se}/∆}{\to }\mathrm{A}\overset{{\mathrm{CH}}_{3}-\mathrm{Cl}}{\underset{{\mathrm{AlCl}}_{3}}{\to }}\mathrm{B}\overset{{\mathrm{CrO}}_{2}{\mathrm{Cl}}_{2}}{\underset{{{\mathrm{H}}_{3}\mathrm{O}}^{+}}{\to }}\mathrm{C}\)


Choose the correct option about maior product

Memory Based Question 28/Jan/25 Evening shift

a

'C' gives Fehling's solution test

b

'C' can be prepared by reacting PhMgBr with \({\mathrm{CO}}_{2}\)

c

'C' gives Tollen's test

d

'C' can give effervescence with \({\mathrm{NaHCO}}_{3}\)

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Q6
PYQ

Which is the correct order of nucleophilic addition
1. Acetophenone,
2. p-nitrobenzaldehyde
3. benzaldehyde,
4. p-tolualdehyde

(Memory Based JEE Mains 24/01/2025 ,Shift -1)

a

1>2>3>4

b

2>3>4>1

c

2 >4>3>1

d

4>3>2>1

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Q7
PYQ

Match List-I with List-II.

List-I

(Reactions)

List-II

(Reagent)

(A)

Hoffmann Degradation

(I)

Conc. KOH, \(∆\)

(B)

Clemmensen reduction

(II)

CHCl3, NaOH/\({\mathrm{H}}_{3}{\mathrm{O}}^{⊕}\)

(C)

Cannizzaro reaction

(III)

Br2, NaOH

(D)

Reimer-Tiemann Reaction

(IV)

Zn.Hg/HCl

Choose the correct answer from the options given below:

a

\(\text{ A - III, B - IV, C - I, D - II}\text{ }\)

b

\(\text{ A - III, B - IV, C - II, D - I }\)

c

\(\text{ A - II, B - I, C - III, D - IV }\)

d

\(\text{ A - II, B - IV, C - I, D - III }\)

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